Organic Chemistry Portal
Organic Chemistry Highlights

Monday, March 23, 2015
Douglass F. Taber
University of Delaware

Reduction of Organic Functional Groups

Cornelis J. Elsevier of the University of Amsterdam developed (ACS Catal. 2014, 4, 1349. DOI: 10.1021/cs4011502) an improved Pd-based protocol for the semihydrogenation of an alkyne 1 to the Z-alkene 2. Yongbo Zhou and Shuang-Fen Yin of Hunan University showed (Adv. Synth. Catal. 2014, 356, 765. DOI: 10.1002/adsc.201300916) that under Cu catalysis, hypophosphorous acid selectively reduced the terminal alkyne of 3 to the ene-yne 4. Hidefumi Makabe of Shinshu University found (Tetrahedron Lett. 2014, 55, 2822. DOI: 10.1016/j.tetlet.2014.03.070) that the iodoalkyne 5 was reduced to the iodoalkene 6 by diimide, conveniently generated from the arenesulfonyl hydrazide. Manat Pohmakotr of Mahidol University used (Eur. J. Org. Chem. 2014, 1708. DOI: 10.1002/ejoc.201301671) P-2 Ni to reduce the sulfoxide 7 to the alkene 8.

Shinya Furakawa and Takayuki Komatsu of the Tokyo Institute of Technology devised (ACS Catal. 2014, 4, 1441. DOI: 10.1021/cs500082g) a Pd catalyst for the selective reduction of the nitro group of 9 to the aniline 10. Hiroshi Kominami of Kinki University employed (Chem. Commun. 2014, 50, 4558. DOI: 10.1039/C3CC49340G) a Ti-promoted Ag catalyst to deoxygenate the epoxide 11 to the alkene 12. Benjamin R. Buckley and K. G. Upul Wijayantha of Loughborough University described (Synlett 2014, 25, 197. DOI: 10.1055/s-0033-1340109) an alternative protocol (not illustrated) for epoxide deoxygenation.

Xiaohui Fan of Lanzhou Jiaotong University observed (Eur. J. Org. Chem. 2014, 498. DOI: 10.1002/ejoc.201301372) that the reduction of 13 to 14 proceeded without cyclopropane opening, suggesting the reaction did not involve substantial charge separation. Michel R. Gagné of the University of North Carolina deployed (Angew. Chem. Int. Ed. 2014, 53, 1646. DOI: 10.1002/anie.201306864) catalytic trispentafluorophenylborane to selectively reduce 15 to 16. Gojko Lalic of the University of Washington reduced (Angew. Chem. Int. Ed. 2014, 53, 752. DOI: 10.1002/anie.201307697) a secondary iodide 17 to the hydrocarbon 18 under Cu catalysis. Primary bromides and triflates could also be reduced, while many other functional groups, including tosylates, were stable.

Marc Lemaire of the Université Claude-Bernard Lyon 1 converted (Tetrahedron Lett. 2014, 55, 23. DOI: 10.1016/j.tetlet.2013.10.065) the nitrile 19 to the aldehyde 20 by V-catalyzed reduction followed by hydrolysis. Matthias Beller of the Universität Rostock showed (Chem. Eur. J. 2014, 20, 4227. DOI: 10.1002/chem.201303989) that a nitrile 21 could be reduced to the amine 22 with very little by-product dimer. Hongwei Gu of Soochow University used (Chem. Commun. 2014, 50, 3512. DOI: 10.1039/C3CC48596J) a Pt catalyst to deliberately prepare the mixed secondary amine 25 from the nitrile 23 and the added primary amine 24.

Neil T. Fairweather of Procter & Gamble and Hairong Guan of the University of Cincinnati devised (J. Am. Chem. Soc. 2014, 136, 7869. DOI: 10.1021/ja504034q) an iron catalyst for the hydrogenation of an ester 26 to the alcohol 27. Victor Snieckus of Queen’s University introduced (Org. Lett. 2014, 16, 390. DOI: 10.1021/ol403183a) an improved in situ preparation of Schwartz's reagent, using it, inter alia, to reduce the amide 28 to the aldehyde 29.

D. F. Taber, Org. Chem. Highlights 2015, March 23.